The invention relates to a pocket lighter having a safety mechanism which may be placed, among others, in a first attitude of use and a second substantially reverse attitude vertical to said first attitude. The pocket lighter comprises a push button which, relative to the operation of the lighter, is moveable between an active position to an inactive position which it tends to maintain; and a cavity in which a portion of said push button is contained, the volume and configuration of which vary depending on the position of the push button.
For several years now the majority of developed countries have regulations precisely defining the conditions of lighters so that they may be considered to be reliable products and may be used within a general field of safety, without special risks for the user. A large majority of countries have recently adopted a common standard, ISO 9994, based on a longtime shared experience with the purpose of protecting the user against misfunctioning of the lighter or any manufacturing defect.
Nevertheless, in certain countries, under pressure from consumer organizations, there has recently been a growth in the demand for lighters incorporating properties warding off the risk inherent in the use of a lighter, as a mechanism specially designed to produce a flame, when it is in the hands of inexperienced users, particularly children under 5 years of age.
This initiative is observed in several lines of action from regulations for correct classification, recommendations to manufacturers to incorporate this type of product in their range and information campaigns addressed to the consumers and particularly to sensitize parents with respect to the risk always involved with having uncontrolled lighters in the home.
It should be clarified, however, that the classification of a lighter as "children-safe" will always be relative, since in accordance with the regulations being developed, a lighter will be thus classified in terms of how low the percentage of children capable of producing a flame in a certain time interval under certain test conditions is.
The incorporation of solutions making them difficult to manipulate by children requires an always difficult balance to be achieved, since if the ignition process is not kept easy, the general public and elderly or physically handicapped persons in particular might adopt other alternative always dangerous lighting methods, such as matches for example. It is, therefore, desirable duly to attain this balance such that the actions to be performed to achieve ignition do not require any special ability while not being obvious to children. Nevertheless, since the lighter is an element designed to produce a flame and, therefore, of potentially dangerous effects, parents and tutors are specially recommended to keep lighters of whatsoever type under control and out of reach of children.
There are known mechanisms such as those disclosed in Spanish patent 8902796, or in European patents 0 291 956 and 0 285 748, of Japanese priority, where concealable levers or elements are provided which the user places at will in a push button blocking position or in a position of free operation of the push button, preventing the release of gas in the former position and placing the lighter in disposition to be ignited in the latter. Nevertheless, these mechanisms have the drawback that they are not capable of returning alone to the blocking position after each operation, with a high risk therefore that the user may forget or voluntarily omit this action. Thus the intended protective aim is not attained, with the aggravation that the lighter is provided with safety conditions that it is not capable of guaranteeing.
Also known are mechanisms such as those described in U.S. Pat. No. 4,717,335, where it is proposed to add a shoulder on the drive wheels of the spark producing flint, which when engaging a protuberance on the support thereof, prevent it from rotating completely. Theoretically, each time the flint is used it is necessary to rotate in the opposite direction to be able to relight it. In practice, this design is fairly inefficient since it is frequently possible to obtain a sufficient number of sparks to obtain a flame without requiring a complete rotation of the flint, whereby a further ignition is possible without having to reset the mechanism. Furthermore, the rotation of the flint wheel in the opposite direction is a sufficiently simple operation to be done accidently by a child, whereby the intended purpose is not achieved.
A further step in the evolution are the solutions proposed in European patent 0 357 347, with US priority or in French patent 2,645,626, where there are levers extending outside the lighter accessible to the user and movable between a position in which the push button and, therefore, the gas flow is blocked and another free operation position, capable of resetting themselves alone to the blocking position after each use. These solutions apparently fulfil the required safety task but on the other hand cause greater assembly difficulties, since the space available for housing a new member between the normal lighter operating members is always small. Furthermore, since these levers project to the outside of the lighter it is also easy that when a child is playing with the lighter, the lever may pass accidentally to the operative position with the consequent risk. Since the size of these levers has, of necessity, to be small, it becomes enormously difficult for lighters with these accessories to be used by elderly people or persons with reduced manual capabilities.